Pope Paul VI
Mense Maio §9
Mense Maio: On Prayers During May for Preservation of Peace
9 As you well know, Venerable Brothers, Our deep concern over this state of affairs is not dictated by any narrow self-interest. Our sole desire is to protect those who are afflicted with misfortune and to promote the true welfare of all peoples. And We nurture the hope that awareness of the responsibilities they bear before God and men will be enough to make heads of government continue their generous efforts to preserve peace; to make every effort to forestall, so far as they can, the obstacles posed to safe, sincere agreement by the course of events or human attitudes.
Source: Mense Maio (Vatican.va)